Self-inductive means for electrical oscillatory circuits.



@E Hf. 1111111311111. SELF INIUTIVE MEANS FUE FLEEIGAL OSOILIg-TORY GIRGUITS.

GpVON APPLLUA'HQR 111mm SMT. 31), 1919;

Patlltd M311'. 9, 1915.4 2 SHBETS-SHEET 1.

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GQ VONvARCC (C R. H. RBNDAL. A SELF INDCCTWB MEANS FCR ELECTRICAL CSCILLATCRY CIRCUITS. APP'IQIOATICN FILED SEPT. 3o, 191C. vL 31,1 87'. Patented Mar. Q, w15.

2 SHEETSSHET z.

l ,iii iti riti-I4 UNITED sTATEs PATENT ortica GEORG von Ance, oF BERLIN, GERMANY, AND RAGNAB. Hanan 'LILIENHOLLL NEAR STOCKHOLM, SWEDEN.

niermann, or'

SELF-INDUCTIVE MEANS FOR ELECTRICAL QSCILLATORY CIRCUITS.'

Specification of Letters Patent.

Y original' application filedV January 29, 1910, Serial uNo. 540,914. Divided and this applicationled September 30, v191.3. vSerial No. 792,682.

To all 107mm it may oacem.'

Be it known that We, Gaone voN ARCO. and RAGNAnHAKAN'RENDAHL, subjects of the German Emperor and the King o' SWeden, respectively', and residing, respectively, at Berlin, Germany, and Lilienholm, near Stockholm, Sweden, have` invented certain.

new and useful Improvements in Self-In# ductive Means for Electrical Oscillatory Circuits, of which the following is a specifi-` cation.

Our invention relates. to selfeinductive meansV for electrical oscillatory circuits, particularly for transmitting arrangements 'in wireless telegraphy, and the like, and the subject matter :of the present invention constitutes a part of -ythe subject matter contained in our co-pending application of .similar title, Serial No.` 540,914, tiled Janupresent apary 29th, 191.0, from Which the plication has been divided.

. The principal feature covered in aforesaid original application comprises substanvtially the forming of self-inductive coils as flat spirals and Winding them out of special Winding elements so lthat the convolutions of the spiral are all located in oneplane.

The'particular object of vthe invention covered by the present divisional applicaven 'on are represented diagrammatically,

' int e accompanying drawings', Wherein- `Figajures 1 and 2 are top plan view and cross section, respectively, showing diagrammatically a coilv formed asl 'an annular disk. Figs. 3 and 4 are perspective viewsshowing two ,I for-ms of4 the Winding .elements in such y coils. Figs. 5 and 6 are diagrams showing eter, Figp? beingan Velevation and Fig. 8'

self-induction within Wide limits. `and 8-show a system of coils according to an arrangement of the coils for varying the Figs.v 7

Figs. 5 and 6,*asse-mbled to form a varioma top plan view,'in which the position of the movable coils when 'swung out, is represented by dotted lines.

Before describing the principal subject matter of the present invention, we shall shortly hereinafter refer to the Winding of,

the coils as disclosed in our aforesaid' origi- -nal application. In said application it is stated that experiments have shownthat the damping of coils, having'thefform of annular disks, is much less when the -Winding is suiiiciently subdivided, than that of the best cylindrical coils. It has been Patented Mar. 9, 1915.

proven by experiment that the least damping action is obtained when the internal di ameter of such coils is approximately one' halfthe external diameter. The 'height of the coils must be small relatively to this `diameter. The conductors forming the coils are stranded together, and sufficiently insulated from each other to prevent the passage of Ilnucault current. The dimensions of the strands and ytheir length are chosen so,

as disclosedin said application, that a selfvinduction coil for high frequency currents is produced which will stand the heaviest possiblev load at minimum damping and maximum self-induction@ n For Winding the coils for heavy loads not oneI strand but a plurality oi' strands connected parallel, is employed each of which is in turn stranded and consists of a large nuniber f Wires oi' at most 02 mm. diameter, insulated from each other for the reasons stated above', the main strands be ing so arranged that they form a fiat ribbon'h as shown in Figs. l and 2. ln this manner not only is a self-induction obtained which is a maximum for a given volume of i coil and a given length of conductor but an exceedingly convenient arrangement of the coils is also produced.

Provision must be made that the individual strands aswell as the individual conductors for'the strands vary their positions in the magnetic field so that each conductor is subject to theisarne averagestreiigth of field. Also the well known tendency of high frequency currents to travel on the outermost surfaces of the conductor is counteracted by the alternation of the position of individual strands relatively to the/ribbon center and by the fine subdivision of the strands into fine individual conductors. To

ich.

each il* tho-rihbon--thus produced may be wound apiraliy around 'a at ribbonlike support of insulating material. The winding element .thus tormed may now be used for any desired forniofwinding. Fig: 3 shows the manner in. which such a winding element 1s fa produced. "'n 'thisgure it indicates a ribvont manner.

bon composed of ten strands connected in parallel and wound spirally around a strip ci press-Spahn,

Eig. 4: shows a ribbon I1. made in a dier tilinearly for a certain distance 'and they thenchange their position from time to time in such manner that for example vthe outer- I most strands are located in the center and the central ones at the outside. Such crossing may take lplace once in every 'convolution. l.

is will be readily understood from the herein described arrangement, to which a large number couldbe added, it is essential that the avere e distance of each of the in* dividual stran from the center of the ribbon remains equal or approximately equal has been clearly described and claimed incoils can-'be brought together.

mitting, capable of producing 'a variation our aforesaid original application.

Variometers .known heretofore in theart comprise individual coils which can be disu placed relatively to each lother in space.-

ihe Variation of the self-induction obtained is larger the nearer all the windings of lthe Their proximity is limited only for mechanical reasons.

These 'variometers, however, do not come` inte consideration for practical purposes for the transmitting circuit in wireless telegraph stations because it is 'impossible to bring the reciprocally movable parts be tween which considerablediiierences of po-- tential exist, so near to each other that a suitable variationl can be obtained For whereas for example in afvariometer for receiving circuits, ayariation ofthe'self in du'ctionpfv 1:17 can be conveniently ob-V tained, itis praeticallygimpossible `to construct a heavy current vaiometer for transof more than 1 :2. For this reason, in spite 'oi' its undisputed advantages, the heavy current variometer has not been introducedin practice 1n wireless telegraphy. v

The Iprincipal object of the. invention Ifarming the .subject matter of' the present application, is to'overcome the above disadvanteges. n I Y Adiccording to ,our invention we distribute the entire-selfinduction amonga plurality of small .varioineters connected in series. in this manneithetensions between the re-l ciprocallynjiqifable parte, of the individual vxmometers fayv'ished so that these The strands are placed rec.

insider partscan he brought nearer together and agreater possibility of 4variation results. Be-

sides the range of variation of the arrangement is materially increased, by the individual variometcrs being formed 'as iat,

superposed coils arranged in pairs, ofv

which one vcoil 'of each pair is arranged fixed and the other movable to swing out fromthe system of coils parallel to the planethereoii. lVe will now explain this arrangement with reference to the diagrams Figs. land 6. In Fig. 5 four coils are shown super osed, of which two, z'. c., al, ag, are fixed an" the two others b1, b2 movable. The coils al, and a2 are wound in one sense and the coils b1 and b2 in the other, yso that the resultant self-induction of the arrangement in this position is zero. The arrows indicatexthe direction of current. ln Fig. Gthe movable coils b1, b2 are swung out in such manner that their opposing influence is removed from the coils al, a2. The result is that the total self-inductance of the variometer -in this position is greater than v.the sum of the inductances of the indiirliduall b2 when lin the position shown in Fig. 6, and' when removed from the other variometer has a certain' maximum self-inductance.

Now the two variometers in this maXimum position are assembled as shownlin Fig. G, their coils are in such position that all coils wound in the same sense indue.` tively react upon each other (al and a2 and b1 and b2 react upon each other), in other words the certain maximum self-inductance of each nariometer is increased by the reaction of the yother -varioineter, so that the total of inductance produced by this arrangement is greater than the sum of the inductances of the individual variometers on account ofthe mutual induct-ancc. Obviously the arrangement may be carried into practice with any desired number of variometers. Likewise, we may use a plurality of groups of movable coils.

In Figs. 7 and 8 adesignates fixed coils and movable coils ofthe form according toFigs. l and 2 wound from ribbons according to Fig, l3 for example. have eyes c for receiving the pivotal axle on which the loose coils swing. The fixed coils a have, in addition, eyes d, throu h los All thev coils .which pins f pass preventing the fixed coils 'and movable coils b are arranged alternately cal oscillatory circuits comprising a plurality of fixed coiis and a plurality of movable coils alternating With the fixed, coils, all of said coils being in inductive relation to each other and all coils being connected electrically in `series so that the drop in potential between two adjacent coils represents only a part oi the Whole drop in potential at the variometer, all of said movable coils being suitably connected to move together for varying the self-induction of the entire system of coils. v

2. A high tension variometer for electrical oscillatory circuits comprising a plurality of fixed coils and a plurality of movablecoils alternating With the fixed coils, all of said coils being in inductive relation to each other and all coilsbeing connected electrically in ,series so that the drop in potential' between two adjacent coils represents only a part of the Whole drop in potential at' the variomey ter, all of said movable coilsl being suitably connected to move together for varying the self-induction of the entire system of coils, each of said coils having the form of an annular .disk i 3. A high tension variometer for electrical oscillatory circuits comprising 'a plurality offixed coils and a plurality "of movable coils alternating with the fixed coils, all of said coils being in inductive relation td each other and, all coils being connected electrically in series so that the drop in potential between two adjacent coils represents onli1 a part of the Whole drop in potential at the variomcter, all of said movable coils being suitably connected to move together or` varying the self-induction of the entire system of coils, each of* said coils having the form of an annular disk, the inner diameter of each coil being substantially equal to one half of its outer diameter.

4. A high tension variometer for electrical oscillatory circuits, comprising a plurality of fixed coils and a plurality of movable coils alternating with the fixed coils, all of said 'coils being in inductive relation to each other, each of said coils having the form of a flat disk, all of said coils being connected electrically in series, the movable coils being Wound to produce fields opposing those pro-- duced by their adjacent fixed coils, all of said movable coils being mechanically ixcd tog ther to permit their simultaneous removal from between the fixed coils for varying the self-induction, said movablecoils being pivoted on an axis at right angles to the plane of the disks and disposed laterally thereof.

5. A high tension variometer for electrical oscillatory circuits, comprising a plurality of fixed coils and a plurality of movable coils, alternating with the fixed coils, and normally in axial alinement therewith, all of said coils being in inductive relation to each other and being electrically connected in series, the movable coils being Wound to produce vfields opposing those produced by their,` adjacent fixed coils, each pair of opposing adjacent movable and xed coils forming an individual variometer, all of the movable coils being mechanically fixed together to permit their simultaneous removal Ifrom alinement nith said. fixed coils for varying the selfinduction of the entire variometer, the maximuni inductance of' the entire variometer, with removed movable coils being larger than the sum of the inductances of the individual Coils, and the minimum inductance of the entire variometer with all coils in :durement being,r substantially only equal to the sum of the inductances of' the individual variometer with its pair of coils in axial alinement.

GEORG vox ARCO.

ltAtiNiiit H A KAN REN'DAHL. W itnesscs y lVoLlu: Mau ll Amir,

f-lxn'rw'ie (l. Nascanna. lVitnesses Gmini Pinar,

l). Cxnnssox. 

